The invention concerns an energy guide chain for guiding hoses, cables or lines, comprising chain links each consisting of two link plates and at least one crossbar connecting the link plates, wherein link plates of adjacent chain links have pivot regions comprising mutually corresponding pivot pins and openings for receiving the pivot pins, by means of which the chain links are pivotably interconnected, and wherein the link plates of adjacent chain links have mutually overlapping overlap regions, forming lines of link plates, wherein the mutually corresponding pivot pins and openings are arranged in the overlap regions of the link plates and wherein at least one link plate is provided with a region of weakened material which permits a variation in length of the chain line beyond the play which occurs in the pivot region in all directions of the link plate.
Energy guide chains are mostly used when the movable connecting point with which at least one consumer is associated is moved linearly along the longitudinal direction of the energy guide chain. Certain tolerances in the straight-line movement of the connecting point can be accommodated by the play in the pivot connections of the chain links.
In comparison, energy guide chains of the general kind set forth are used in areas of application in which the movable connecting point performs a significant motion transversely with respect to the longitudinal direction of the energy guide chain, more specifically simultaneously with or subsequently to a linear movement in the longitudinal direction of the chain. That transverse movement can be in the range of the width of a chain link or can be a multiple thereof.
GB 1 580 892 and DE 198 39 575 A1 disclose energy guide chains of the general kind set forth, in which the openings in the chain link plates for accommodating the chain link plates are oval or in the form of a slot so that the pivot regions have an increased play, in the longitudinal direction of the chain, in comparison with a direction which is perpendicular to the longitudinal direction of the chain in the main plane of the link plates. That additional play permits an increase in the length of the line of chain link plates.
Additional play in the pivot regions however involves the disadvantage that this worsens the properties of the energy guide chain, in terms of the straight-ahead movement thereof. Thus for example energy guide chains in which the top run is laid on the bottom run involve an increased danger of the top run slipping off the bottom run. Corresponding problems arise also in the case of a self-supporting top run or in other modes of operation with the energy guide chain. In addition the increased play in the pivot region means that the pivot connection between the link plates is subjected to a higher rate of wear.
Therefore the object of the present invention is to develop energy guide chains of the general kind set forth, in which the movable connecting point can perform a transverse movement with respect to the longitudinal direction of the energy guide chain, to such an effect that the energy guide chains enjoy improved properties in terms of straight-ahead movement, while being of a structurally simple design configuration and affording a long service life.
That object is attained by an energy guide chain in which the region of weakened material is in the form of an elastically deformable region of the link plate. Elastic deformation of the regions which in accordance with the invention are introduced into the link plates permits a variation in the length of the line of the chain, beyond the free play which occurs in the pivot region, but an elastic return force is opposed to the variation in length, the elastic return force improving the properties in terms of straight-ahead movement of the chain. It will be appreciated that the elastically deformable regions can also be provided in relation to openings for accommodating the pivot pins, which are of an oval cross-section, an elongate cross-section or a cross-section which is enlarged in another fashion.
The variation in length of the line of the chain can be effected by the link plates themselves experiencing a variation in length or by the connecting region of adjacent link plates being extensible. Therefore, the additional introduction of the elastically deformable region means that there can be a variation in position of a region of the energy guide chain transversely with respect to the longitudinal direction of the chain, which is markedly greater than is permitted in itself by the free play occurring in the pivot region of the chain links, without the pivot regions being excessively loaded in continuous operation of the chain. When the energy guide chain is of a given length, the movable connecting point can thus perform a markedly greater transverse movement which, over a length of a few chain links, for example four to ten chain links, without being restricted thereto, already permits lateral displacement of the movable connecting point by the width of a chain link.
The introduction of the elastically deformable regions means that the length of the line of link plates of the energy guide chain, which is associated with those regions, can be varied when a force acts thereon, that is to say it can be stretched or upset, thereby permitting bending of the energy guide chain transversely with respect to the longitudinal direction thereof. It will be appreciated that in that way the chain link plates of the oppositely disposed line thereof are also subjected to the action of deformation forces which are to be absorbed in the pivot regions or by deformation of the link plates themselves. The elastically deformable regions of the chain can be arranged on the inwardly and/or outwardly curved side of the chain, in the event of a transverse movement thereof, so that one of the lines of link plates is upset or stretched or both lines vary their length in mutually opposite relationship, with respect to the neutral fiber of the chain.
The design configuration in accordance with the invention of the energy guide chain can be advantageous irrespective of the nature of its mounting, that is to say in a lying position but also when it is mounted in a lateral position or when the energy guide chain is disposed in a hanging or standing arrangement, that is to say when the direction-changing region which connects the mutually oppositely disposed runs forms the highest or the lowest region of the energy guide chain, or in the case of an energy guide chain which can be laid down in a zig-zag configuration. The pivot angle for example of link plates which are adjacent in a straight or angled position can be limited by abutments which are preferably arranged on the link plates and which can be formed in one piece thereon. The measures according to the invention can be implemented in relation to energy guide chains which are to be displaced linearly or along a circular arc, wherein in the latter case the chain links can be of an angled configuration, wherein the variation in length of a line portion of the chain, which goes beyond the play in the pivot regions, permits movement with a reduced or increased radius of curvature.
In accordance with a preferred embodiment there are provided link plates which between the pivot connections of the mutually oppositely disposed overlap regions of the chain link plate have elastically deformable regions extending over the entire height of the link plate, preferably perpendicularly to the longitudinal direction of the link plate. The elastically deformable region is preferably in the form of a cross-sectional constriction so that this region acts in the manner of a film hinge. The weakening of material can be afforded also by using a material of increased elasticity or by another element which permits a variation in length and preferably at the same time a variation in angle, which preferably exerts resilient return forces on the parts of the chain link plate which have experienced a change in position. Preferably the elastically deformable region is uniform over the entire height of the link plate. Such a weakening of material permits the pivot regions, as was hitherto usual, to have an only slight play, which affords the chain advantageous running properties, and at the same time also permits the adjoining parts of the plate to assume an angled configuration and possibly also to involve upsetting thereof. In addition the greater extent of the stretch region means that material fatigue phenomena are reduced.
The film hinge can be for example in the form of a groove of V-shaped or substantially round cross-section, with a spread angle of about 45-90xc2x0. The constriction can be to ⅕-xc2xd of the mean thickness of the link plate, without being restricted thereto.
The elastically deformable region disposed between the pivot connections of the link plate can be arranged in particular adjacent to the means for accommodating the pivot pin of the adjacent chain link, that is to say adjacent to the location at which the forces resulting in the variation in length of the line of the chain act on the link plate which is reversibly variable in length under the effect of a force thereon.
In accordance with an advantageous development the cross-sectional constriction can have mutually spaced regions which, with respect to the main plane of the associated link plate, have a lateral displacement relative to each other and which permit an increase in the length of the link plate, with a reduction in the lateral displacement. The regions can be in the form of an outwardly displaced portion in the nature of an arcuate film bridge or stretch fold, in which case the two ends of the arc are arranged at and for example formed on oppositely disposed regions of the associated link plate, those regions being separated by the cross-sectional constriction. The arc can be open inwardly or outwardly with respect to the interior of the energy guide chain and can be displaced inwardly or outwardly in the central region with respect to the fixing regions of the arc to the associated link plate portions, so that the central portion of the arc projects inwardly or outwardly beyond the fixing regions. The arc can thus be for example of a U-shaped, V-shaped or W-shaped configuration, which can apply for the side surfaces of the arc, which are both towards and away from the interior of the chain. In this arrangement the side surfaces of the elastically deformable region can extend substantially parallel to each other. In addition the arc can be of a cross-section which is substantially constant over the length of the arc. When the chain link plate is increased in length or upset, the arc is flattened or the flanks of the arc become steeper, wherein lateral displacement of the central portion of the arc in relation to the fixing regions of the arc takes place at the respective link plate portions. The arc-like film hinge therefore permits at the same time a variation in length and angle of the adjacent link plate regions relative to each other. Alternatively, lateral displacement of regions of the cross-sectional constriction can be achieved by the provision of a film hinge-like region which, with oppositely disposed ends, is mounted to and for example formed on the adjacent regions, which are variable in position relative to each other, of the respective link plate, at differing lateral spacings relative to the inside surface of the link plate. The film hinge is thus disposed inclinedly relative to the longitudinal direction of the link plate. A variation in length of the link plate can thus cause a slight lateral displacement relative to each other of the regions of a chain link plate, which are separated by the cross-sectional constriction.
The film hinge-like region of the link plate is preferably arranged completely within the cross-section of the substantially non-elastic adjoining regions of the link plate.
In accordance with a further advantageous embodiment, there are provided link plates or at least one plate which at the regions adjoining the openings for receiving the pivot pins, comprise an elastically deformable material, wherein elastic deformability can be based for example on a reduced thickness of material or the elastic properties of the material used. The regions of weakened material can be arranged on the side of the openings, which is towards the ends of the link plates. The elastically deformable regions can thus permit a variation in length of the corresponding line of link plates of the chain, upon a movement of the energy guide chain in the transverse direction, with compression thereof. In that way the pivot pin can move out of its reference position in the usual regular travel movement of the chain which is defined in particular by the link plate geometry (for example straight link plates in the case of chains for straight-ahead motion) and can thus permit lateral bending of the chain by a large degree, with a variation in the length of the line of chain link plates.
In accordance with a further advantageous embodiment the regions of weakened material can be in the form of pivot pins comprising an elastically deformable material which permits a variation in length of a line of chain link plates, with deformation of the pivot pins. Deformation of the pivot pins can be effected by elongation thereof and/or by upsetting of the diameter thereof. For that purpose there can be provided for example a region of the pivot pin involving a material which has a higher modulus of elasticity or a higher degree of compressibility than the adjoining material of the link plate or the oppositely disposed pivot pins of the chain link. The pivot pins can also be of smaller thickness than the pivot pins of the oppositely disposed link plate of the chain link, in which case the respective receiving means for the pivot pins can be identical, and the pivot pins can also have incisions to permit relative movement of adjacent link plates in the longitudinal direction of the chain. The pivot pins can be formed in one piece on the link plates or they can be formed separately.
Advantageously the pivot pins are guided with only slight play in the receiving means transversely with respect to the longitudinal direction of the link plates in order to prevent torsional movements of adjacent chain links relative to each other.
If the arrangement has cranked chain links having a region which is set back towards the interior of the chain and a region which projects towards the exterior of the chain, wherein the set-back and projecting regions of adjacent chain links can overlap each other, in accordance with a further embodiment the connecting region of the projecting and set-back portions of the chain link can be in the form of an elastically deformable region which extends over the entire height of the link plate and which is of increased elastic deformability in comparison with adjoining regions. The connecting region of the cranked chain links is of a substantially Z-shaped configuration so that, with a weakening of the material of that region, there can be a variation in the length of the link plate, with a change in the angle of the individual limbs of the connecting region. In that case the link plates are preferably designed in such a way that between the regions extending substantially in the longitudinal direction of the chain, there is a connecting region which extends perpendicularly thereto.
The ends of the link plates can have in the overlap region on the side towards the overlap region of the adjacent link member bevels or openings which permit deflection of the chain links in the transverse direction with respect to the energy guide chain. In particular the overlap regions provided with pivot pins can converge conically towards the ends. That configuration is particularly advantageous when the link plates do not have any elastically deformable region which extends over the entire height thereof and which results in easier angular positioning of the two overlap regions of a chain link relative to each other. In a corresponding manner the outwardly disposed overlap region of the chain link can be provided at its inside with a recess which is of the greatest depth in the middle region of the link plate.
The configuration of the link plates according to the invention can be provided both in relation to cranked link plates and also in relation to lines comprising alternate inner and outer link plates. The energy guide chain can comprise two or more trains or lines of link plates, wherein one line is made up exclusively of link plates in which there are no elastically deformable regions permitting an excessive variation in length of the line of link plates, wherein all or some of the link plates of the oppositely disposed line thereof have corresponding elastically deformable regions. The proportion of the link plates with elastically deformable regions, which make up a line thereof, makes it possible to adjust deflection of the energy guide chain in the transverse direction, which occurs when a given force is acting on the chain. Thus for example chain links with elastic regions can alternate with conventional link plates or can be respectively arranged in alternately disposed groups each having the same or different numbers of link plates of the same type. Particularly when the arrangement has link plates with elastic regions which permit a variation in length of the line of link plates, wherein the elastic regions are embodied by a reduced material thickness or a higher degree of elasticity of the corresponding material, it is possible to provide chain links in which both oppositely disposed link plates are provided with a corresponding elastic region. In particular both link plates of a chain link can be provided with material-weakened regions extending over the total height of the link plate, for example in the form of film hinge-like cross-sectional constrictions or connecting regions of suitable configuration in respect of overlap regions of the link plates, which are cranked forward and back, but also with pivot regions of suitable configuration. In order to achieve a significant variation in length of the line of the chain with link plates of that kind, corresponding forces which exceed a limit value have to be applied to the line of the chain, wherein return forces are produced by elastic deformation of the regions which permit the variation in length of the line of the chain. Chains of that kind thus have good travel properties in straight-ahead movement, when, in one or more chain links, both link plates are provided with regions involving a weakening of material.
The link plates of a chain link can be connected by substantially rigid crossbars which are preferably formed in one piece thereon or which can also be secured in position by retaining means. The crossbars can also be adapted to be twistable or can be of a divided design configuration.
It is possible to provide chain links having divided crossbars which have corresponding projections and openings which engage one into the other, wherein the projection on a crossbar region is pivotable through an angular range relative to the other crossbar region in the main plane of the crossbar, which is parallel to the longitudinal direction of the chain and perpendicular to the link plates. At the same time the opening is provided with an undercut configuration which engages behind the projection so that the separate crossbar regions are secured to prevent longitudinal displacement relative to each other in the longitudinal direction of the crossbar, at least after a certain play or practically without play.
The material-weakened regions are preferably arranged at the parts of the link plates, which are provided with openings for receiving pivot pins.
It will be appreciated that the various embodiments of the elastic regions can also be embodied in different combinations in one and the same chain link or in one and the same link plate.
In order to permit stable movement or stable guidance of the chain in spite of the elastic regions, adjacent chain link plates of a line of link plates are advantageously connected together by means of a snap connection, thereby ensuring a secure and simple connection between the link plates, in particular when the chain involves transverse displacement. Advantageously, for that purpose the pivot pin is provided with retaining means and is designed for example in the manner of a press stud or is provided with securing springs, wherein the retaining means are advantageously disposed at the free ends of the pins so that they are prevented from being pulled out of the corresponding openings. Preferably the corresponding opening is provided over the entire extent thereof in the longitudinal direction of the link plate, with a groove or undercut configuration for receiving the retaining means.
However, other snap connections between link plates are also possible, for example if the front ends of the link plates are received at the adjacent chain link by a groove, so that the pivot pin of the respective link plate snaps into the corresponding opening, as is described for example in DE 195 12 088.
With the exception of the elastic regions according to the invention which permit an increase in the length of the line of link plates, the link plates of the energy guide chain according to the invention can be substantially rigid and flexurally stiff or can have a certain degree of lateral deformability. The longitudinal elastic deformability of the lines of link plates is made possible predominantly or practically exclusively by the elastic regions according to the invention.
It will be appreciated that the lines of link plates of the energy guide chain according to the invention can comprise cranked link plates or alternately arranged inner and outer link plates, without being limited thereto.
The invention further concerns a guide structure for the energy guide chain according to the invention, which can be in the form of a guide channel with oppositely disposed side walls and a bottom support. The guide structure can include fixing means for fixing to a carrier structure. The guide structure has straight guide profiles which are oriented in mutually parallel relationship, arranged laterally of the energy guide chain, over a part of the length of the guide structure, for receiving a region of the energy guide chain which is arranged in a straight configuration, wherein the guide profiles are arranged at the small spacing of the energy guide chain. The assembly also has at least one guide profile (possibly a plurality thereof) which includes an angle relative to the longitudinal direction of the guide profiles which are arranged straight, so that the straight guide region of the guide structure is adjoined by a guide region which is of an angled or arcuate configuration.
The guide profiles which adjoin the straight guide profiles at an angle in the longitudinal direction can have a different angle to the straight guide profiles, on opposite sides of the guide structure. That permits a transverse movement of the energy guide chain over an angular region and is restricted thereto, wherein there is a continuous transition in the guide structure to a guide region which only permits a longitudinal movement of the energy guide chain and which limits the transverse displacement to a slight amount, for example in the region of the width of a line of link plates of the energy guide chain. The regions of the guide structure, which are set in an angled position, can be angled towards one or both sides of the guide structure. The angled region of the guide structure can have a bottom support for the energy guide chain, but there can also be only a lateral guidance effect afforded by the guide structure.